对在终端输入的单个字符进行分类

#include <stdio.h>

int main (void)
{
    char c;
    printf ("Enter a single character:/n");
    scanf ("%c", &c);

    if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
        printf ("It's an alphabetic character./n");
    else if (c >= '0' && c <= '9')
        printf ("It's a digit./n");
    else
        printf ("It's a special character./n");

    return 0;
}